1. Field of the Invention
The present invention relates to a shake correction apparatus and an imaging apparatus which includes the shake correction apparatus.
2. Description of the Related Art
Conventionally, a camera having a zoom unit that moves a plurality of optical lenses so as to change an imaging magnification is widely used (see Japanese Patent Laid-Open No. 2001-324663). In Japanese Patent Laid-Open No. 2001-324663, a plurality of lens holding units configured to hold a plurality of lenses is moved in the optical axis direction by a cam ring, and the movement of the lens holding unit in its rotational direction is regulated by a rotation regulating unit. With this arrangement, the optical lens can be moved to a defined position.
In recent years, high-magnification cameras have rapidly advanced. As the high-magnification camera advances, image blur, which causes a photograph taken by the operator to be blurred, may occur due to vibration, so-called “hand shake”, imparted to the camera by the operator when a photograph is taken particularly at the telescopic side. As a countermeasure, a method in which an image pickup element is moved in a direction perpendicular to the optical axis so as to cancel such vibration has been known (see Japanese Patent Laid-Open No. 2008-160175). A method in which an image pickup element is moved in a direction perpendicular to the optical axis so as to synchronize a lens group in a lens barrel group with hand shake to cancel such vibration has also been known (see Japanese Patent Laid-Open No. 2008-209434).
However, in the method disclosed in Japanese Patent Laid-Open No. 2008-160175, an image pickup element such as a CCD image sensor, a CMOS image sensor, or the like is to be directly moved, which uses peripheral space due to the relationship with an actuator to be driven, resulting in a tendency for the size of device to increase.
Also, in the method for moving a lens group disclosed in Japanese Patent Laid-Open No. 2008-209434, a lens group to be moved is generally operated as one block. Conventionally, it is known that the insertion of an iris diaphragm and a shutter between the lens groups is effective in decreasing the size of the overall optical system. Space may occur in one lens group for an optical configuration, and the overall optical system can be reduced in size by the effective utilization of such space.
However, it is difficult to operate lens groups in which an iris diaphragm and a shutter are inserted therebetween as a shake correction lens group due to the size reduction. In other words, the diaphragm and the shutter include a mechanism and an actuator for driving them, resulting in a tendency for both the size and the weight to increase. Therefore, when they are forced to be operated together with the shake correction lens group, an actuator for a shake correction operation is increased in size. Consequently, it becomes difficult to decrease in the size of the overall optical system, resulting in higher power consumption.